Climate Prediction Center - Week 3-4 Outlook

Prognostic Discussion for Week 3-4 Temperature and Precipitation Outlooks
NWS Climate Prediction Center College Park MD
300PM EDT Fri Oct 31 2025

Week 3-4 Forecast Discussion Valid Sat Nov 15 2025-Fri Nov 28 2025

La Niña conditions are currently present, with equatorial sea surface temperatures (SSTs) below average across most of the Pacific Ocean. Low-level wind anomalies were easterly over the east-central and western equatorial Pacific Ocean, with westerly anomalies over a small region in the eastern equatorial Pacific. Upper-level wind anomalies were westerly over the western equatorial Pacific. Enhanced convection and precipitation were evident over the regions between Indonesia and northern Australia, while suppressed convection and precipitation were observed near the Date Line. La Niña conditions are favored to persist through December 2025 – February 2026, with a transition to ENSO-neutral likely (55% chance) during January – March 2026. The Madden-Julian Oscillation (MJO) index was weak and mostly inside the unit circle during late September and early October,and became more amplified by mid-October with eastward propagation to the Maritime Continent. Both the GEFS and ECMWF ensembles show continued eastward propagation of the MJO signal to the Pacific during early November. However, ensemble spread becomes large for the amplitude of the RMM index. This growing ensemble spread is likely due to destructive interference with the ongoing La Niña. The Weeks 3–4 Temperature and Precipitation Outlooks are based primarily on operational dynamical model guidance, including the GEFSv12, CFSv2, ECMWF, and JMA, as well as the predicted evolution of the pattern from the Week-2 forecast.

Dynamical model 500-hPa height anomaly forecasts during Weeks 3–4 show a fairly consistent evolution from Week-2 forecasts. A blend of the ECMWF and GEFSv12 500-hPa height pattern forecasts, plus a contribution from the Multivariate Linear Regression (MLR) height forecast based on the MJO RMM index, ENSO, and decadal trends, features a broad anomalous trough over the Bering Sea and Mainland Alaska, extending southeastward to the Gulf of Alaska and the Pacific Northwest. Above-average 500-hPa height anomalies and anticyclonic flow are forecast over most of the eastern contiguous United States (CONUS). Near-normal 500-hPa height anomalies are forecast over most of the central and western CONUS. Below-average height anomalies are forecast over Mainland Alaska, the Aleutians, and Southeast Alaska. Near-normal 500-hPa heights are predicted over Hawaii.

Enhanced chances for above-normal temperatures are predicted over the central and eastern CONUS due to generally near- to above-normal 500-hPa height anomalies and along with support by most of the dynamical temperature forecast tools and an experimental manual blend of GEFSv12, CFSv2, JMA, ECMWF, and the MLR tool. Probabilities favoring above-normal temperatures reach 50% for parts of the Southern Plains. Equal chances (EC) of near-, above-, or below-normal temperatures are forecast across parts of the western CONUS as a trough is predicted over the Gulf of Alaska extending eastward to the western CONUS during the latter part of the period. Above-normal temperatures are favored over eastern Mainland Alaska and Southeast Alaska, consistent with most of the temperature forecast tools.

The Weeks 3–4 Precipitation Outlook favors above-normal precipitation over the Pacific Northwest and northern California, extending eastward to the Upper and Middle Mississippi Valley and the Great Lakes region, in association with a trough predicted over the North Pacific and cyclonic flow over the Great Lakes region. Below-normal precipitation is likely over the southeastern CONUS due to above-normal 500-hPa heights, supported by most of the dynamical precipitation forecast tools. A majority of the dynamical guidance favors a tilt toward near- to above-median precipitation over parts of southern Mainland Alaska and Southeast Alaska, ahead of a trough predicted over the Gulf of Alaska, consistent with most precipitation forecast tools.

Above-average SSTs and dynamical model guidance favor above-normal temperatures across the Hawaiian Islands (Kauai, Oahu, Maui, and the Big Island) during Weeks 3–4. Below-normal precipitation is favored for Kauai and Oahu, while equal chances of below, near, or above-normal precipitation is forecast for Maui and the Big Island, supported by most of the dynamical precipitation forecast tools.

Forecaster: Luke He

The next week 3-4 outlook will be issued on Friday, Nov 07, 2025

These outlooks are based on departures from the 1991-2020 base period

These are three category outlooks consistent with what is currently used for the monthly and seasonal forecasts.

The shading on the temperature map depicts the most favored category, either above-normal (A), below-normal (B), or near-normal (N) with the solid lines giving the probability ( >33%) of this more likely category (above, below, or near).

The shading on the precipitation map depicts the most favored category, either above-normal (A), below-normal (B), or near-normal with the solid lines giving the probability ( >33%) of this more likely category (above, below, or near).

In areas where the likelihoods of 2-week mean temperatures and accumulated precipitation amounts are similar to climatological probabilities, equal chances (EC) is indicated.